Biomedical subjects

C J Calhoun

Publications and source records attributed to C J Calhoun.

3 recordsLinked to original sources

PubMed1991

Standardizing the weaning process.

The goal among critical care staff of discontinuing mechanical support in a prudent and expeditious manner emerges immediately after intubation. This goal, known as the weaning process, contains the three phases of optimizing the patient's condition, assessing and evaluating the patient's progress, and diagnostic testing. As a diagnostic test, the wean trial needs to be standardized for efficiency and safety. To maximize safe and efficient delivery of the trial, the primary nurse and respiratory therapist should be the responsible professional monitors. The standardized trial enhances staff confidence for safe extubation. A successful standardized weaning protocol eases the transition from mechanical ventilation to spontaneous breathing for the patient and improves the professional performance and confidence of critical care staff.

Clinical Protocols↗

PubMed1990

Cytoplasmic microinjection of immunoglobulin Gs recognizing RNA helices inhibits human cell growth.

We report here that nucleolar and cytoplasmic RNA in mammalian cells is recognized specifically by both experimentally induced monoclonal IgG unique for left-handed Z-RNA and by autoimmune mouse monoclonal IgG specific for ribosomal RNA. Nucleolar Z-RNA synthesis, like nucleolar ribosomal RNA synthesis, is inhibited by actinomycin D treatment and dimethylsulfoxide-induced differentiation. Immune anti-Z-RNA IgGs microinjected into living nuclei bind nucleolar RNA, and these complexes appear to be removed from the nucleus within minutes. Cytoplasmically microinjected monoclonal or polyclonal anti-Z-RNA IgGs specifically bind cytoplasmic RNA and inhibit cell multiplication. Microinjection of antibodies directed against double-stranded RNAs. Elevated ionic conditions, which in energy-minimized models can cause the walls of the groove in Z-RNA (but not Z-DNA) to approach each other and close, also prevent antibody binding to specific synthetic or cellular Z-RNA determinants. Our antibodies binding unique Z-RNA structures probably recognize antigens determined by the exposed 2'-OH ribose sugar-phosphate groups.

Animals↗

PubMed1987

Cytoplasmic Z-RNA.

Specific immunochemical probes for Z-RNA were generated and characterized to search for possible Z-RNA-like double helices in cells. Z-RNA was detected in the cytoplasm of fixed protozoan cells by immunofluorescence microscopy using these anti-Z-RNA IgGs. In contrast, autoimmune or experimentally elicited anti-DNA antibodies, specifically reactive with B-DNA or Z-DNA, stained the nuclei. Pre-or nonimmune IgGs did not bind to the cells. RNase A or T1 digestion eliminated anti-Z-RNA IgG binding to cytoplasmic determinants; however, DNase I or mung bean nuclease had no effect. Doxorubicin and ethidium bromide prevented anti-Z-RNA antibody binding; however, actinomycin D, which does not bind double-stranded RNA, did not. Anti-Z-RNA immunofluorescence was specifically blocked in competition assays by synthetic Z-RNA but not Z-DNA, A-RNA, or single-stranded RNAs. Thus, some cytoplasmic sequences in fixed cells exist in the left-handed Z-RNA conformation.

Animals↗